Multi-Strategy Question Answering System for NTCIR-7 C-C Task

In NTCIR-7, ACLIA task focus on more complex questions than factoid ones. To participate in Monolingual Chinese task, we propose a multi-strategy QA system that can handle questions with different types. Basic steps of this system are described as follow: first, pattern-based question type analysis is performed to classify questions of four types, then an Information Retrieval method is utilized to retrieve and re-rank documents that may contain correct answers; after that, we deal retrieved results with different strategies including heuristic rules, pattern matching and web knowledge bases; finally, nuggets are extracted from answer candidates and formed as the results. The evaluation result shows that our system achieves 43.29% average F-score(beta=3).